The invention relates to an air-intake tube system for internal combustion engines.
Such air-intake tube systems are used for increased power and torque performance in motor-vehicle internal combustion engines and represent an important component thereof.
For internal combustion engines with straight or V-type cylinder configuration, these air-intake tube systems cover almost the entire available space above the cylinders of the internal combustion engine, and thus accessibility to the other engine components, such as injection valves, the fuel-distribution system, exhaust-gas recirculation valves, temperature and pressure sensors, and the like are no longer accessible for necessary maintenance without removal of the entire air-intake tube system.
Starting from this situation, an object of the invention is to provide an air-intake tube system which permits ready accessibility for maintenance of components of internal combustion engines which are covered by the air-intake tube system.
The above and further objects are achieved by incorporating a separate, removable unit in the air-intake tube system which will provide access to the engine components below the system when the unit is removed.
In accordance with the invention, the air-intake tube system comprises a body having a pair of intake ducts for each cylinder and a unit separately and detachably engageable with the body for cooperating with the ducts to control the length of an air flow path to the cylinder. When the unit is engaged with the body it forms a closed chamber or manifold therewith into which intake air can be supplied. The intake ducts each have one end with a flange for connection to the cylinder and an opposite end adapted for connection to the closed chamber to form a first path for flow of air from said closed chamber to the cylinder. Each duct has an intermediate shortcut aperture directly connecting the interior of the inlet duct and the chamber to form a second, shorter air flow path to the cylinder. The unit has valve means for selectively opening and closing the shortcut apertures, and when closed the first longer path of air flow to the cylinder is established and when open the second, shorter path of air flow is established. The unit comprises upper and lower flanges which are seated on the body to enclose the chamber or manifold when the unit is engaged with the body. The lower flange forms an open clearance space therebelow with the inlet ducts in ducts for accommodating components associated with the engine, the components being accessible when the unit is disengaged and separated from the body.